I am resurrecting a K2 that was in pretty bad shape. At least one person had taken it apart before, a few screws and such were missing and the lensboard was sitting off kilter (i.e. I have never seen the lensboard mounted properly). It is coming back together nicely but the focusing is an enigma.
The lensboard is mounted on four jackscrews. Turning the focus knob rotates the jack nuts and the jackscrews do what jackscrews do. At infinity the lensboard sits back about as far as it will go. A ground glass mounted on the film gate confirms that the focus is correct. But the focus knob doesn't stop at 360 degrees. It turns about 630 degrees or 1-3/4 turns. Racked the whole way out it focuses at about 3-1/2 feet which would certainly be about right (although the closest mark is 1.7 meters). But the the marks on the focus knob have no correlation to the actual distance as the knob has now gone 1-3/4 turns.
Everything turns smoothly and seems to work as it should. I didn't tear it down to the guts of the focusing mechanism, but I took everything else apart and it still wasn't clear how to access the gearing. I'd really rather not do that as the actual focus is correct now, just the scale is wrong.
Any insights or observations would be appreciated.
The lensboard is mounted on four jackscrews. Turning the focus knob rotates the jack nuts and the jackscrews do what jackscrews do. At infinity the lensboard sits back about as far as it will go. A ground glass mounted on the film gate confirms that the focus is correct. But the focus knob doesn't stop at 360 degrees. It turns about 630 degrees or 1-3/4 turns. Racked the whole way out it focuses at about 3-1/2 feet which would certainly be about right (although the closest mark is 1.7 meters). But the the marks on the focus knob have no correlation to the actual distance as the knob has now gone 1-3/4 turns.
Everything turns smoothly and seems to work as it should. I didn't tear it down to the guts of the focusing mechanism, but I took everything else apart and it still wasn't clear how to access the gearing. I'd really rather not do that as the actual focus is correct now, just the scale is wrong.
Any insights or observations would be appreciated.